malfunction TOYOTA PRIUS 2014 3.G Service Manual

5
When trouble arises
505
5-2. Steps to take in an emergency
PRIUS_OM_OM47857U_DVD_(U)
Warning lightWarning light/DetailsCorrection
procedure
Tire pressure warning
light
When the light comes
on:
Low tire inflation pres-
sure such as
• Natural causes ( P. 507)
• Flat tire ( P. 530) Adjust the tire
inflation pressure
to the specified
level.
The light will turn
off after a few
minutes. In case
the light does
not turn off even
if the tire infla-
tion pressure is
adjusted, have
the system
checked by your
Toyota dealer.
When the light comes
on after blinking for 1
minute:
Malfunction in the tire
pressure warning sys-
tem
(  P. 509) Have the system
checked by your
Toyota dealer.
Master warning light
The warning light comes
on and flashes to indicate
that the master warning
system has detected a
malfunction. 
P. 5 1 3

5
When trouble arises
507
5-2. Steps to take in an emergency
PRIUS_OM_OM47857U_DVD_(U)
■
Electric power steering system warning light (warning buzzer)
When the 12-volt battery charge becomes insufficient or the voltage tempo-
rarily drops, the electric power steering system warning light may come on
and the warning buzzer may sound.
■ If the malfunction indicator lamp comes on while driving
First check the following:
● Is the fuel tank cap loose?
If it is, tighten it securely.
The malfunction indicator lamp will go off after several driving trips.
If the malfunction indicator lamp does not go off even after several trips, con-
tact your Toyota dealer as soon as possible.
■
When the tire pressure warning light comes on
Check the tire inflation pressure and adjust to the appropriate level.
Pushing the tire pressure warning re set switch will not turn off the tire
pressure warning light.
■The tire pressure warning light may come on due to natural causes
The tire pressure warning light may come on due to natural causes such
as natural air leaks and tire inflat ion pressure changes caused by tem-
perature. In this case, adjusting the tire inflation pressure will turn off the
warning light (after a few minutes).
■When a tire is replaced with a spare tire
The compact spare tire is not equipped with a tire pressure warning
valve and transmitter. If a tire goes flat, the tire pressure warning light will
not turn off even though the flat tire has been replaced with the spare
tire. Replace the spare tire with the re paired tire and adjust the tire infla-
tion pressure. The tire pressure wa rning light will go off after a few min-
utes.

5
When trouble arises
511
5-2. Steps to take in an emergency
PRIUS_OM_OM47857U_DVD_(U)
CAUTION
As an added safety feature, your
vehicle has been equipped with a tire
pressure monitoring system (TPMS-ti re pressure warning system) that
illuminates a low tire pressure telltal e (tire pressure warning light) when
one or more of your tires is significantly under-inflated. Accordingly,
when the low tire pressure telltale (tire pre ssure warning light) illumi-
nates, you should stop and check your tires as soon as possible, and
inflate them to the proper pressure. Driving on a significantly under-
inflated tire causes the tire to overheat and can lead to tire failure.
Under-inflation also reduces fuel effi ciency and tire tread life, and may
affect the vehicle’s handling and stopping ability.
Please note that the TPMS (tire pressure warning system) is not a sub-
stitute for proper tire ma intenance, and it is the driver’s responsibility to
maintain correct tire pressure, even if under-inflation has not reached the
level to trigger illu mination of the TPMS low tire pressure telltale (tire
pressure warning light).
Your vehicle has also been equipped with a TPMS (tire pressure warning
system) malfunction indicator to indi cate when the system is not operat-
ing properly. The TPMS (tire pressure warning system) malfunction indi-
cator is combined with the low tire pressure telltale (tire pressure
warning light). When the system det ects a malfunction, the telltale will
flash for approximately one minute an d then remain continuously illumi-
nated. This sequence will continue upon subsequent vehicle start-ups as
long as the malfunction exists. When the malfunction indi cator is illumi-
nated, the system may not be able to detect or signal low tire pressure
as intended.

512 5-2. Steps to take in an emergency
PRIUS_OM_OM47857U_DVD_(U)
CAUTION
TPMS (tire pressure warning system) malfunctions may occur for a vari-
ety of reasons, including the installation of replacement or alternate tires
or wheels on the vehicle that prevent the TPMS (tire pressure warning
system) from functioning properly. Always check the TPMS (tire pres-
sure warning system) malfunction te lltale after replacing one or more
tires or wheels on your vehicle to ensure that the replacement or alter-
nate tires and wheels allow the TPMS (tire pressure warning system) to
continue to function properly.
NOTICE
■Precaution when installing a different tire
When a tire of a different specification or maker is installed, the tire pres-
sure warning system may not operate properly.

514 5-2. Steps to take in an emergency
PRIUS_OM_OM47857U_DVD_(U)
Stop the vehicle immediately.A buzzer sounds and a warning message is shown on the multi-infor-
mation display. The following warnings indicate the possibility of dam-
age to the vehicle that may lead to an accident. Immediately stop the
vehicle in a safe place and contact your Toyota dealer.
Warning messageDetails
Indicates an abnormal engine oil pressure. The warning light may turn on if the engine oil pres-
sure is too low.
Indicates a malfunction in the hybrid system.

5
When trouble arises
515
5-2. Steps to take in an emergency
PRIUS_OM_OM47857U_DVD_(U)
Have the vehicle inspected immediately.
Failure to investigate the cause of the following warnings may lead to
the system operating abnormally and possibly cause an accident.
Have the vehicle inspected by your Toyota dealer immediately.
Warning messageDetails
(If equipped) Indicates a malfunction in the LED headlight system.
Indicates a malfunction in the P position control sys-
tem.
In this situation, there is a possibility that the parking
lock mechanism will not work.
When parking, park the vehicle on a flat surface and
apply the parking brake securely. Also, it may not be
possible to turn the “POWER” switch off. If this hap-
pens, applying the parking brake will enable the
switch to be turned off.
Indicates that the cooling performance of the hybrid
battery is low.

516 5-2. Steps to take in an emergency
PRIUS_OM_OM47857U_DVD_(U)
Warning messageDetails
(Flashes)
(If equipped) Indicates a malfunction in the pre-collision system.
A buzzer also sounds.
(Flashes)
(If equipped) Indicates a malfunction in the radar cruise control sys-
tem.
A buzzer also sounds.
Press the “ON-OFF” button once to deactivate the
system, and then press the button again to reacti-
vate the system.
(Flashes)
(If equipped) Indicates a malfunction in the LKA.
A buzzer also sounds.

524 5-2. Steps to take in an emergency
PRIUS_OM_OM47857U_DVD_(U)
Have the malfunction repaired immediately.After taking the specified steps to correct the suspected problem,
check that the warning message and light turn off.
Interior buzzerExterior buzzerWarning messageDetailsCorrection procedure
Once 
(Comes on for 15 seconds.)
(Flashes) The electronic
key is not
detected when
attempting to
start the hybrid
system.
Confirm
the loca-
tion of the
electronic
key.
Once 3 times (Flashes)An open door
other than the
driver’s door is
closed while the
electronic key is
outside the
detection range
and the
“POWER”
switch is in
ACCESSORY
or ON mode.
Confirm
the loca-
tion of the
electronic
key.

5
When trouble arises
545
5-2. Steps to take in an emergency
PRIUS_OM_OM47857U_DVD_(U)
If the hybrid system will not start
Reasons for the hybrid system not starting vary depending on the
situation. Check the following a nd perform the appropriate proce-
dure:
■ The hybrid system will not start even though the correct
starting procedure is being followed ( P. 194)
One of the following may be the cause of the problem:
● The electronic key may not be functioning properly.
*
(  P. 548)
● There may not be sufficient fuel in the vehicle’s tank.
Refuel the vehicle. ( P. 4 0 )
● There may be a malfunction in the immobilizer system.
*
(  P. 138)
● There may be a malfunction in the P position control system.
*
( P. 199, 515)
*: It may not be possible to shift the shift position from P to other posi-
tion.
■ The interior lights and headlight s are dim, or the horn does
not sound or sounds at a low volume
One of the following may be the cause of the problem:
● The 12-volt battery may be discharged. ( P. 550)
● The 12-volt battery terminal c onnections may be loose or cor-
roded.

546 5-2. Steps to take in an emergency
PRIUS_OM_OM47857U_DVD_(U)
Emergency start functionWhen the hybrid system does not start, the following steps can be
used as an interim measure to start the hybrid system if the
“POWER” switch is functioning normally: Set the parking brake.
Turn the “POWER” switch to ACCESSORY mode.
Press and hold the “POWER” switch for about 15 seconds
while depressing the brake pedal firmly.
Even if the hybrid system can be started using the above steps, the
system may be malfunctioning. Have the vehicle inspected by your
Toyota dealer.
■ The interior lights and headlights do not turn on, or the horn
does not sound
One of the following may be the cause of the problem:
●One or both of the 12-volt ba ttery terminals may be discon-
nected.
● The 12-volt battery may be discharged. ( P. 550)
Contact your Toyota dealer if the problem cannot be repaired, or if
repair procedures are unknown.
STEP 1
STEP 2
STEP 3